The southern Moroccan passive continental margin: An example of differentiated long-term landscape evolution in Gondwana
The southern Moroccan passive continental margin: An example of differentiated long-term landscape evolution in Gondwana
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摩洛哥南部被动大陆边缘：冈瓦纳大陆差异化长期景观演化的一个例子
DOI：
10.1016/j.gr.2017.03.013
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发表时间：
2018
影响因子：
6.1
通讯作者：
O. Kluth
中科院分区：
文献类型：
--
作者：
Manuel Sehrt;U. Glasmacher;D. Stockli;H. Jabour;O. Kluth
东北偏东走向的反阿特拉斯山脉带揭示了近期地形的变化，海拔> 3公里，表明了差异化的长期景观演变。为了解开沉降和折返的历史，低温热年代学已被应用于21个样本从前寒武纪基底的伊尔赫姆，Kerdous，伊夫尼，和巴斯德拉内层。热年代学数据表明，一个共同的地质演化的西部反阿特拉斯。锆石裂变径迹年龄（287（± 23）~ 331（± 24）Ma）表明，在晚石炭世-早二叠世期间，华力西褶皱和褶皱后侵蚀作用导致了一次主要折返。锆石（U-Th）/He（205-287 Ma）和磷灰石裂变径迹（120-219 Ma）数据与中大西洋裂谷和漂移阶段有关，因为Anti-Atlas形成了裂谷系统的折返肩。岩石隆起和折返阶段一直持续到早白垩世，其中9公里的前寒武纪-古生代覆盖层已被侵蚀。热模拟显示，在整个白垩纪有一个较小的沉积埋藏（1.5-2.5公里），与Cenomanian-Turonian时期北方非洲的广泛海侵一致。磷灰石（U-Th-Sm）/He年龄在49（± 3）~ 164（± 10）Ma之间，证实了Anti-Atlas西部最近的小折返，Atlasian造山带的影响越来越大，从西南到东北可能存在反映该地区地形差异的地幔柱异常。
The ENE-trending Anti-Atlas mountain belt reveals variation in recent topography with elevations of > 3 km indicating a differentiated long-term landscape evolution. To unravel the subsidence and exhumation history, low-temperature thermochronology has been applied on 21 samples from the Precambrian basement of the Irherm, Kerdous, Ifni, and Bas Drâa inlier. Thermochronological data suggest a common geological evolution of the western Anti-Atlas. Zircon fission-track ages from 287 (± 23) to 331 (± 24) Ma point to a main exhumation in the Late Carboniferous–Early Permian assigned to the Variscan folding and post-folding erosion. Zircon (U-Th)/He (205–287 Ma) and apatite fission-track (120–219 Ma) data are related to the Central Atlantic rift and drift stage, as the Anti-Atlas formed the exhumation shoulder of the rift system. The rock uplift and exhumation phase lasted up to the Early Cretaceous, whereby 9 km of Precambrian–Palaeozoic overburden has been eroded. Thermal modelling reveals a minor sedimentary burial (1.5–2.5 km) throughout the Cretaceous, in accordance with the widespread transgression across the northern Africa in the Cenomanian–Turonian. Apatite (U-Th-Sm)/He ages between 49 (± 3) and 164 (± 10) Ma confirm recent minor exhumation in the western Anti-Atlas with an increasing impact of the Atlasian orogeny and potentially a mantle plume anomaly from southwest to northeast reflecting the differentiated topography in the area.